Former All Black Jerry Collins has been arrested in Japan on charges of illegally carrying a kitchen knife in a department store, police said on Sunday.

The 32-year-old, who played for New Zealand in 48 international games from 2001 to 2008, including the 2003 and 2007 World Cups, was arrested on Saturday in the central industrial city of Hamamatsu, police said.

According to press reports, Collins caught a security guard's attention when he went behind a sales counter at the store.

When approached, the New Zealander pulled out the 17-centimetre blade from his pocket and placed it on the counter.

It is illegal to have weapons with blades longer than 15 centimetres without police permission in Japan.

Collins, who captained a test match against Argentina in 2006 and scored two tries in the 2007 Rugby World Cup, told police that he "kept the kitchen knife for self-defence", according to the reports.

Collins played for Yamaha Jubilo in Japan's Top League from 2011 and left the team last month when his two-year contract expired.